San Diego firm hits targets for complex lasers

Dennis Huynh, a Cymer technician and quality assurance expert performs the final checks on an Extreme Ultraviolet light source vessel before shipment to a customer. The light source unit is part of an Extreme Ultraviolet scanner used to pattern semiconductor chip during production.
— Howard Lipin

Dennis Huynh, a Cymer technician and quality assurance expert performs the final checks on an Extreme Ultraviolet light source vessel before shipment to a customer. The light source unit is part of an Extreme Ultraviolet scanner used to pattern semiconductor chip during production.
— Howard Lipin

San Diego's Cymer has spent a decade and more than $500 million trying to develop a new type of laser so semiconductor makers can build smaller, cheaper and more power-efficient chips for devices like handsets and tablet computers.

It’s been a tricky optical physics problem, carving new ground for precisely bending extreme ultraviolet light. Cymer’s lasers blast droplets of tin, which burst into tight wavelengths of light used in the process of etching microscopic circuit patterns on silicon wafers.

Because this new laser technology has taken so long to develop, some doubt has crept into the semiconductor industry over whether extreme ultraviolet lasers — or EUV — would ever be viable in mass-production chip assembly lines.

Analysts say the industry has a lot riding on the success of EUV. ASML, a semiconductor equipment supplier based in The Netherlands, has agreed to buy Cymer for $2.5 billion. Both companies say the deal aims to accelerate EUV development. The sale is awaiting clearance from antitrust regulators. It’s expected to be completed in the first half of this year.

In addition, Intel, Samsung and other semiconductor makers have invested more than $4 billion in ASML to ensure the next generation of production equipment is developed.

“The race is not about tomorrow,” said Sergis Mushell, a microprocessor analyst with industry research firm Gartner. “It’s about the generation after that. But the industry has put its weight behind EUV. Intel has put its money down. They obviously want to expedite this.”

At a conference last month, Cymer showed off what it has accomplished so far in its development of extreme ultraviolet, or EUV, laser systems. While the technology still isn’t ready for prime time, the company thinks the milestones it has reached should convince naysayers that it’s on the path to success.

“If you looked over the past year, from where the technology was to where we have gotten to, we have jumped over some hurdles,” said Blake Miller, a Cymer spokesman. “This has gotten to the point where there are fewer and fewer people who say, ‘Well, this may never happen.’ ”

EUV is hard-core technology. Cymer’s EUV systems fill a room. They cost millions of dollars each. And they are used in one of the very first, critical steps in making chips that power smartphones, tablets, computers and other devices.

That first step is printing the tiny circuitry lines on silicon. The process is akin to darkroom photography. A chemical is placed on a silicon wafer and acts like photo film. A pattern mask of circuits is then exposed to a certain wavelength of light from a laser, which etches the pattern on the wafer.

Over the past four decades, chip circuit patterns have gotten progressively smaller, following Moore’s Law — a technology industry axiom named after Intel co-founder Gordon Moore. It says chip performance doubles about every two years.

The forward march of Moore’s Law means computer memory is inexpensive today and top-end smartphones have more computing power than was available to put a man on the moon.

Taking the next step to make chips even smaller has been a technological challenge. Yet it’s vital for the industry that is increasingly going mobile.

“Mobile means battery-operated devices, and we want to make these devices work longer and longer,” said Mushell of Gartner. “The only way to do that is to have (chip) geometries that are smaller and smaller.”

For years, Cymer has been a market leader in making semiconductor production lasers used by giant chip makers such as Intel and Samsung. The company’s current lasers, known as Deep Ultraviolet lithography, produce lines in circuit patterns to carry electrical current down to about 32 nanometers in size.

To get an idea of how small that is, a very fine human hair is about 10,000 nanometers wide.

To go even smaller than that, Cymer is focused on EUV technology.

A key hurdle for EUV lasers has been ratcheting up power levels for mass production. Chip makers want to run their assembly lines as fast as possible. The more power flowing through EUV lasers, the less time a silicon wafer needs to be exposed to the light, which allows semiconductor makers to speed up production.

What is EUV?

Extreme ultraviolet: An advanced lithography used in a semiconductor production line to etch lines on silicon. It has a shorter light wavelength, 13.5 nanometers, than current lithography lasers, which are reaching their limits in terms of shrinking circuit patterns.

The chips produced with EUV: Light sources are projected to be as much as 100 times faster than today’s most powerful computer chips, with 1,000 times the memory capacity. Flash memory devices and dynamic random access memory (DRAM) devices are expected to be early adopters of EUV technology.

Source: Cymer

Chip makers eventually want EUV lasers to blast wafers at 250 watts of power. For much of past year, the best Cymer and others have been able to produce is 10 watts. At that power level, the wafer must sit in front of the light beams for a relatively long time before the circuit pattern takes.

“These (laser) machines are attached to a lot of other machines in that production line,” said Mushell. “You probably have $20 million or $30 million (in equipment) patched together. If one slows down, it slows everything down.”

In late February, Cymer ran one of its EUV laser systems in a demonstration for six hours at 40 watts of power. It delivered stable doses of light.

It also demonstrated a one-hour run at 55 watts with similar dose stability.

“The jump to 40 watts is a significant boost and the next step in the timeline for EUV power sources,” said Dean Freeman, a research vice president at Gartner.

Cymer technician work on a Extreme Ultraviolet laser at the company's factory in San Diego
— Howard Lipin

Cymer technician work on a Extreme Ultraviolet laser at the company's factory in San Diego
— Howard Lipin

There’s a long way to go. But Cymer thinks it will be able to boost the power of EUV lasers to meet chip makers’ needs.

“Our goal is to reach 250 watts next year,” said Nigel Farrar, vice president of lithography application development at Cymer. “The fact that we’ve validated that it works up to the 40-watt to 50-watt level, it’s very encouraging in terms of future scaling.”

Chip makers had hoped to begin using EUV lithography this year or next. But delays in getting the technology in the field at sufficient power levels has led many chip makers to now expect EUV production to ramp up later.

In the meantime, chip makers have been using tricks to extend the life of existing chip production equipment, such as double patterning, to keep reducing chip size.

“EUV is the next big thing and has been for a long time,” said Jim Handy, an analyst with market research firm Objective Analysis. “But these people who do (semiconductor production,) who are geniuses, they have figured out ways to forestall having to go to EUV.”

While these tricks can be used to make smaller chips, they also require another process in the production system.

“With EUV you can do this in one pass, and as a result the cost is lowered significantly — provided the throughput of the EUV system is high enough,” said Freeman of Gartner.

Cymer believes it will get where it needs to be with EUV. In the past year, it went from 10 watts of power to 50 watts, a five times improvement.

“If you go from 50 watts to 250 watts, that’s another five times,” said Miller, the Cymer spokesman. “I think we have shown that we understand a lot of the parameters that we have to tweak to get to that higher power level. Now it’s just a lot of engineering. It’s no longer solving difficult physics problems.”